In a typical irrigation system, a plurality of sprinklers are provided for distributing water to irrigate a selected terrain area. One type of irrigation sprinkler is a pop-up irrigation sprinkler. Pop-up irrigation sprinklers are typically buried in the ground and include a stationary housing and a riser assembly, mounted within the housing that cycles up and down during an irrigation cycle. During an irrigation cycle, the riser assembly is propelled through an open upper end of the housing and projects above ground level, or “pops up,” to distribute water to surrounding terrain. More specifically, pressurized water is supplied to the sprinkler through a water supply line attached to an inlet of the housing. The pressurized water causes the riser assembly to travel upwards against the bias of a spring to the elevated spraying position above the sprinkler housing to distribute water to surrounding terrain through one or more spray nozzles. When the irrigation cycle is completed, the pressurized water supply is shut off and the riser is spring-retracted back into the sprinkler housing so that the housing and riser assembly are again at and below ground level.
A rotary sprinkler commonly includes a rotatable turret mounted at the upper end of the riser assembly. The turret typically includes one or more spray nozzles for distributing water and is rotated on an adjustable arcuate part-circle or full circle water distribution pattern.
Rotary sprinklers commonly include a water-driven motor to transfer energy of the incoming water into a source of power to rotate the turret. One common mechanism uses a water-driven turbine and a gear reduction system to convert the high speed rotation of the turbine into relatively low speed turret rotation. Some examples of rotary sprinklers include the sprinklers described in U.S. Pat. Nos. 4,625,914; 4,787,558; 5,383,600; 6,732,950; and 6,929,194 all assigned to the assignee of this application, Rain Bird Corporation.
Rotary sprinklers are designed to accept a variety of nozzles depending on the desired range and spray coverage of the emitted stream of irrigation water. Some nozzles make use of multiple nozzles or nozzle outlets providing varying water flow characteristics and trajectories. These rotary sprinklers commonly include a cavity in the form of a nozzle socket for slide-fit reception of nozzles. The nozzle socket allows a user to remove and replace the nozzles when a nozzle offering different flow or trajectory characteristics is desired or if a nozzle becomes damaged during use. Nozzles are typically retained in the nozzle socket by use of one or more retainer screws that may be inserted into the turret to hold the nozzle in place and which may be removed for removal of the nozzle. In one such system, the screw may be a diffuser screw positioned at the nozzle discharge end to retain the nozzle and restrict it from becoming discharged from the opening of the nozzle socket when subjected to fluid pressure, while at the same time acting as an adjustable stream diffuser by being positioned with at least a portion of the screw extending into the flow path of the water stream. A water stream exiting a sprinkler is energized to reach a relatively far throw distance, but often causes a donut pattern of watering around the sprinkler because only a small amount of the energized water falls to the terrain along the radius adjacent to the sprinkler. Thus, the diffuser screw acts to retain the nozzle within the nozzle socket and to interrupt an upper portion of the water stream, de-energizing the portion and causing it to fall through the water stream to water the terrain in a radius generally adjacent to the sprinkler.
While current nozzle retention methods are generally suitable for ordinary operation of the sprinkler, these methods tend not to work in all situations. For example, if a screw retaining the nozzle within the nozzle socket is also used as a stream diffuser, a user, while attempting to adjust the length of the screw extending into the water path, may inadvertently remove the screw from its retaining engagement of the nozzle. Because typical nozzles held within nozzle sockets cannot generally withstand water pressures above about 30 psi when the diffuser screw is not in retaining engagement with the nozzle, a nozzle under these circumstances may become unintentionally discharged from the nozzle socket under typical operation pressures of about 40-50 psi. Moreover, during particularly harsh operations of the sprinkler system, like winterization processes, wherein nozzles may be subjected to unusually high pressures of up to 100 psi, the nozzle may become unintentionally discharged from the nozzle socket. For example, this may occur because the frictional forces are not sufficient or the retaining screw may be out of position. Each of these situations may cause inconvenience and potential added expense to a user who may be required to search for a discharged nozzle or replace the nozzle if it cannot be located. Additionally, improvements in nozzle outlets have provided for close range watering without the use of a diffuser screw. Thus, in some situations, it may be desirable to use a sprinkler without a diffuser screw which may de-energize the water stream, reducing the sprinkler's range.
Therefore, there exists a need for a nozzle for an irrigation sprinkler that can be quickly and easily installed and removed from the sprinkler. Further, there is a need for a nozzle that can be securely mounted to the sprinkler without becoming unintentionally discharged during normal operation and maintenance of the irrigation and without the need for a diffuser screw.